Printing telegraph receiver



May 12, 1931. R. TEVlS PRINTING TELEGRAPH RECEIVER Filed April 19. 1927 2 Sheets-Sheet. 1

W E 3 WE vw. R

May 12, 1931. R..TEVIS 1,805,114

RINTING TELEGRAPH RECEIVER Filed April 19. 1927 2 SheetsSheet 2 hi l INVENTOR ROBERT TEV/r ATTbRNEY.

atented ay 12, 1931 PATENT orrlcr.

ROBERT TEVIS, F J'AIvIAICA, NEW YORK, ASSIGNOR OF SIX-TENTHS T0 EDWIN B.

LAPH AM, OF HOBOKEN, NEW JERSEY PRINTING TELEGRAPH RECEIVER Application filed April 19, 1927. Serial No. 185,055.

My invention relates to printing telegraphs and has for an object to provide a system adapted to be actuated by the ordinary Morse signals or by the signals of an arbitrary code 5 or alphabet.

1 I am aware that a great many type printing systems and apparatus have been developed. Heretofore the most successful of these systems have called for special apparatus at the transmitting station, as well as at the receiving station, and have involved the use of synchronized motors in the two apparatus. The difficulty of keeping a motor at the receiving end in perfect synchronism with the motor at the transmitting and has been one of the serious drawbacks to the success of these systems. It is an object of my invention to overcome this difficulty by providing a receiving apparatus that does not have to be carefully attuned to or synchronized with a transmitting apparatus.

Another object of my invention is to provide a printing telegraph system which involves no moving parts, other than relay armatures between the main line wire and the magnets or solenoids operating the type bars.

Another object of my invention is to provide a printing telegraph which will be controlled by the ordinary Morse signals. One of the advantages of such a system lies in the fact that. my receiving apparatus may be plugged into any receiving station or into any telegraph line without disturbing existing apparatus. Because my apparatus may be operated by Morse signals it will respond to signals sent by hand. However, for high speed work it will be obvious that mechanical transmission could be employed.

Another advantage of providing a printing telegraph which will respond to Morse signals lies in the fact that much time is saved in transmission, because the length of the signals is inversely proportional to the frequency of use, i. e. the most used letters are composed of a single impulse, the next most used of two impulses, the third most used of three impulses, etc. I am aware of the fact'that telegraph systems have been developed in which series of relays are made to respond to various combinations of dot and dash impulses,

permitting much higher speedof transmis- Still another advantage of employing Morse signals lies in the fact that the telegraph, operators are trained to the sound of such signals and can read them on local relays, unless they. are transmitted at exceedingly high speed. Thus local operators can check the operation of my receiver and determine at any time whether anythinghas gone wrong.

Another object of my invention is to provide a system which Wlll clear the line after each complete signal has been sent so that if through any mistake on the part of the operator or through any fault or interruption of service in the line, a signal is jumbled, the error will not be carried over to the next signal sent. For instance in certain systems heretofore developed, a combination of six impulses is required for each character transmitted, the six impulses being necessary 1 to produce a complete rotation of a controlling wheel at the receiving station. If then an impulse failed to reach the receiving station by reason of a momentary interruption in the line, due to meteorological conditions or any other causes, the control wheel would fail to complete its rotation at the end of the signal, but would wait for an impulse of a succeeding signal before printing the signal and thereafter all the successive signals would be incorrect. This difficulty is overcomeby my invention. Each signal whether composed of one, two or more impulses, Wlll operate the printing mechanism, and after the signal has'been sent the line is cleared for the next signal. In other words it is impossible to carry overthe impulses from one signal to another. c

Another object f my invention is to provide a system in which printing of the characters transmitted is controlled by the time interval between signals. In other systems it has been necessary to send a printing impulse over the line in addition to the impulses representing the various characters. By m invention I avoid the use of an additional printing impulse and insure the printing of a signal as soon as the time .interval between impulses exceeds a predetermined limit. To this end I provide a slow acting relay which measures the time interval between impulses and operates the printing relays whenever the interval exceeds the space permissible betlween the impulses of a multi-impulse signa Another object of my invention is to provide a system in which a single interval-measuring relay suffices for signals of any number of impulses within the limits of the system.

Another object of my invention is to provide a system in which a single impulse-measuring relay serves to distinguish between dot and dash impulses, no matter how many impulses (within the limits of the system) constitute a complete signal.

lVhile I prefer to use the International Morse code, I'can use any other code composed of two kinds of impulses with relatively short intervals between the impulses and longer intervals between complete signals.

With the above named objects in view and other which will appear hereinafter, I shall now describe an embodiment of my invention andshall define the novelty and scope of my invention in the appended claims.

The accompanying drawings,

Fig. 1 is an electrical diagram illustrating a referred form of my invention; and

ig. 2 is a diagram on an enlarged scale of a portion of Fig. 1.

In general I provide a series of solenoids, one for each character to be printed, these solenoids are adapted to operate type bars or other suitable printing mechanism in the usual well-known manner and hence the printing mechanism, which forms no part of my invention, is not illustrated. The electrical impulses from the sending station are received by a relay, which, in turn, closes the circuit of a slow acting relay. The purpose of the latter relay is to measure the length of each impulse and thus distinguish between dots and dashes. At the end of each impulse another slow acting relay is energized which measures the length of the intervals between impulses so as to distinguish between the intervals within a signal and intervals between signals. For practical purposes it is necessary to provide for signals up to and including four impulses each, as combinations of dots and dashes up to thirty are thereby provided. However. my system could be expanded to cover signals of five or more impulses so as to increase the numbeiof combinations to any extent desired. I providefour banks of switching relays, the

end of a complete signal, the second slow acting relay causes the selected ty'pe actuating magnet to be energized, and the armatures of all the relays are then restored to normal position ready for the next signal.

In the accompanying diagrams a line wire, over which electrical impulses from the transmitting station are received, is indicated at 10. Connected in series with the line wire is a relay 11 provided with an armature 12 which plays between two contacts 13 and 14, being held normally in engagement with contact 13 by a spring 12'. The armature is permanently connected with a battery line 15 which extends from one terminal of a local battery 16, the other terminal of the battery being grounded. The contact 13 constitutes one terminal of a slow acting relay 17, the other terminal of which runs to a contact point 18. The contact 14 forms one terminal of another slow acting relay 19, the other terminal of which is grounded. The relay 1'? is adapted to measure the interval between impulses and may be termed a space relay while the relay 19 is adapted to measure the length of the impulses and may be termed the dash relay.

Whenever an impulse comes over the line 10 the circuit of the relay 19 is .closed and an armature 20 is attracted and moved into engagement with a contact 21 connected to the local battery line 15. The relay 19, however, is relatively slow in its action and the armature will not engage the contact 21 unless the impulse is of a pre-determined length. Thus when a-dot is sent over the line the impulse is too short to close the circuit through the contact 21 and only when a dash is sent over the line will the contact be closed. A spring 22 acts on the armature 20 and serves to withdraw it to normal position shown in the diagram as soon as the circuit through the contact 14: is broken. In fact the relay is so designed that while the armature 20 comes up to closed position relatively slowly it is returned to normal position very quickly. Hence a rapid succession of short impulses coming over the line 10 will not have a cumulative efi'ect tending to close the circuit through the contact 21, and only an impulse of relatively long duration will effect the closure of the contact.

The slow acting relay 17 operates in a maning through the magnet 11 has ceased, for it will be recalled that the circuit through the relay 17 is closed at the point 13 only when the magnet 11 is de-energized. But there is another break in the circuit of the relay 17 at the contact point 18 so that normally no flow takes place through the relay 17 until after an impulse has been sent through the line 10 and has operated certain switching relays [presently to be described. If the intervals between impulses are shorter than a pre-determined length-:the relay 17 will not have time to draw the armature 24 into engage ment with the contact 25. At each throw of the armature 12 in response to an impulse through the relay 11 the circuit through the relay 17 will be broken at the contact point 13 and a spring 26 will withdraw the armature 24 to the position shown in the diagram, breaking the circuit at the contact point 25. The relay 17 is arranged to draw the armature 24 to contacting position relatively slowly, but the armature will be returned by the spring 26' practically instantly, so that no cumulative effect will permit the armature 24 to be drawn up into contacting position by a series of closely spaced impulses passing through the relay 17. i

' In connection with the three relays 11, 17, and 19, I provide four banks of switching relays a, b, c, and d adapted to respond to opposed windings which for convenience I.

the first, second, third, and fourthimpulses, respectively 'coming. over the line 10. The banks, a, b, and 0 each comprise three relays. Thus the first bank a includes a relay 30a, 31a, and 32a, the second bank I) the relays 30b, 31b, and 32b and third bank 0, the relays 30c, 31c, and 320. The fourth bank (1 comprises a single relay 31d. The relays 31a, 31b, 31c, and 31d, are polarized and are provided with shall call positive and negative windings respectively.

Referring now to the first bank a, the relay 32a and the positive winding 31a of relay 31a are connected in series with the relay 11. The circuit may be traced from the relay 11 through the line 33a, armature 34a of the relay 30a and by way of a contact point 35a, against which armature 34a normally bears, ,to the positive winding 31'a, thence by way of a lead 36a to relay 32a and by way of a lead 37a to ground. Thus when an impulse comes over the line 10 the polarized relay 31a is energized to draw its armature 38a to the: left, as viewed -in' the diagram, and simultaneously the relay 32a is energized and attracts an armature 39a.

The armature 38a is grounded and when it is drawn to the-left it engages a contact 400: and closes a circuit through the relay 30a. This circuit may be traced from the battery line 15, by way of a lead 4111 through the relay 30a, and thence by way of a lead 42a, contact 40a, and armature 38a to ground. When the relay 30a is energized the armature 34a is attracted, breaking the circuit of the positive winding of the polarized relay 31a at the contact point 35a. However, current continues to flow through the relay 3211 as long as the line impulse continues but through another path which will now be described. The armature 39a carries a contact member 43a insulated therefrom and connected by a lead 44a to the line 33a. When the relay 32a is energized the contact member 43a engages a contact point 45a connected to the lead 36a and current now finds a new path from the line 33a by way of lead 44a, member 4301., contact 45a through the winding of the relay 32a and thence by way of the lead 37a to ground.

The armature 34a carries a contact member 46a insulated therefrom and connected to ground. l/Vhen the relay 30a is energized the contact member 46a engages the contact 18, so that as soon as the line impulse ceases and the armature 12 engages the contact point 13, a circuit will be completed toground' through the slow relay 17 This circuit may be traced from the battery line 15, through a lead 47 to the armature 12 and thence by way of contact point 13, relay 17, contact point 18 and member 46a to ground. If the duration of the interval after the impulse exceeds a certain limit the relay 17 will have time to draw the armature 24 into engagement with the contact point 25 and certain other relays which will be described later, will then be energized to operate the printing mechanism and to clear the system for the next signal. It will be understood of course that the armature 38a'of the polarized ,relay will remain in contact with the contact point 40a until an impulse through the negative winding 31"a of the polarized relay 31a serves to restore it to the normal position shown in the diagram. This negative winding and those of all the other polarized relays to be described below are energized immediately after a type actuating solenoid has been energized.

As soon as the impulse over the line 10 ceases, relay 32a is de-energized and the armature 39a is withdrawn by the spring 49a. Now if a second impulse comes over the line before the space relay 17 has had time to clear the system, this impulse will by-pass the polarized relay 31a and relay 32a and will proceed to the second bank of switching relays, because the armature 34a, when at- 34a carries only one insulated contact mem ber 46a while the armature 346 carries two contact members 54?) and respectively,

which are insulated from each other and also from the main body of the armature. The contact member 54?) is permanently connected to the line 27 and hence to the armature 24 of the space relay 17, while the contact member 55?) is permanently connected to the line 23 and hence to the armature 20 of the dash relay 19. A spring 565 acting on the armature 34?), holds the latter normally in engagement with contact point 356 and members 54b and 55?) with contacts 575 and 586 respectively. The contact point 576 is connected by line 59a with one terminal of a relay 6011, the other terminal of which is connected to ground by means of the ground line 61. The contact point 58?) is connected by a line 62a with one terminal of the positive winding of a polarized relay 63a the other terminal of which is grounded.

The course taken by the second impulse of a signal may now be traced as follows: From the relay 11 the line impulse flows through the lead 33a, armature 34a (which is now being held in the lefthand position), contact point 50a, line 51a, armature 39a, contact point 52a, line 33b, armature 34?), contact point 356, positive winding 31b of the polarized relay 31?), line 36b, relay 3%, and lead 376 to ground. Thus the relay 32b is energized to attract its armature 39?) against the action of the spring 49?). The armature 396 carries a contact member 43?) insulated therefrom and connected by a lead 44,?) tovthe line 335. When the armature 39b is attracted by the relay 3% the contact member 43?) engages a contact point 45?) which is connected to the line 36b and the line impulse now continues through the relay 3% by way of contact member 43?) and contact point 456. Simultancously with the energizing of the relay 321), the positive winding of the polarized relay 81?) is energized and the armature 38b is thereby drawn to the left, as viewed in the diagram, engaging a contact 40?) and thereby closing a circuit through the relay 306. This circuit may be traced from the battery line 15 by way of line 4179, relay 30a, line 42?), contact point 40?), armature38b, and thence to ground. As soon as the relay 30b is energized the armature 34b is drawn to the left as viewed in the diagram against the tension of the spring 56?), thereby disengaging the contact points 35?), 57b and 58b and engaging contact points 50?), 64b and 656.

If the signal includes a third impulse said impulse will pass through the same course as the-second impulse so far as the armature 346 but thence will continue through the contact point 50?), line 51b, armature 39?), contact point 526 and thence by way of a line 330 to the armature 340 of the third bank of switching relays. The arrangement of bank a is identical with that of bank 6 and corre-v sponding parts are indicated by the same reference numerals bearing the suffix 0 instead of b. It will be noted that the contact point 647) is permanently connected to the contact member 540 carried by the armature 340 while the contact point 65?) is permanently connected to the contact member 550. The armature 34c normally engages the contact point 350 and the insulated members 54c and 55!; carried by the armature 34:0 normally engage contact points 570 and 580 respectively. The contact point 570 is connected by a line 59b to one terminal of a relay 6071, the other terminal of which is connected to the ground wire 61. The contact point 580 is connected by a line 62b to one terminal of the positive winding of a polarized relay 636, the other terminal of which is grounded.

The third impulse of a signal would bypass relays 31a, 32a,'31b, and 32b and would aifect the bank 0 in the same way that the second impulse affected the bank 6. If the signal were to contain a fourth impulse, the latter would pass from the armature 340 through the contact point 500, line 510, armature 39c, contact point 520, and thence by way of line 33d to the fourth bank.

The fourth bank, as explained above, consists of a single polarized relay with a postive or locking winding and a negative or resetting winding. The positive winding 3ld is connected at one terminal to the line 33d while the other terminal is grounded. The polarized relay 31d has an armature 38d bearing two contact members 54d and 5561?. These contact members are insulated from each other. The contact point 640 is permanently connected to the contact member 54d and the contact point 650 is permanently connected to the contact member 55d. The contact members 54d and 55d normally engage contact points 5701 and 5801 respectively. The contact point 570! is connected by a line 590 to one terminal of a relay 600, the other terminal of which is connected to ground wire 61. The contact point 580! is connected by a line 620 to one terminal of the positive winding of a polarized relay 630, the other terminal of which is grounded. When the positive winding of the polarized relay 31d is energized the contact points 5703 and 58d are disengaged and the members 54d and 55d now make contact with contact points 6M and 6503 respectively. The contact point. 64d is connected by a line 5901 to one terminal of a relay d, the other terminal of which is connected with the ground wire 61. The contact point-d is connected by a line 62d to one terminal of the positive winding of a polarized relay 630?, the other terminal of which is grounded. Q

As explained above any form of printing mechanism may be employed with my selector apparatus. The purpose of the apparatus is to selectively control the actuation of the proper keys, type bars, or other printing mechanism corresponding to the-characters represented bythe signals sent from the transmitting station. To control a printing mechanism I have indicated in the diagram a set of thirty solenoids. These solenoids could just as well be magnets, motors, or any other electrically operated controlling or working mechanisms.- The solenoids are ar-' ranged in four groups; the first group may consist of two solenoids which are respectively actuated by single impulse signals. Thesecond group may consist of four solenoids adapted to be actuated respectively by double impulse signals; The third group may consist of eight solenoids adapted to be actuated respectively by triple impulse signals and the fourth group may consist of sixteen solenoids adapted to be actuated by quadruple impulse slgnals, respectively. I prefer to use the International Morse code of signals which is composed of various combinations of long and short impulses, but my system can also be applied to other established codes or to an arbitrary code. In order to simplify the explanation of my system I have indicated the solenoids in the va- 'rious groups by using alphabetical characters .Z1, Z2, Z3 and Z4.

corresponding to those which the solenoids when actuated would cause to be. printed were the International Morse code employed. Thus in the first or single impulse group we have two solenoids T and E, the first being energized when a dash or impulse of long duration comes over the line and the second (E) when an impulse of short duration or a dot comesover the line. The second group consists of solenoids A, M, N and I which are actuated respectively by a dot, and a dash, a dash and a dash, a dash and a dot, and two dots. The third group of solenoids will re spond to the Morse signals for U, K, O, W, R, G, D, and S. While the fourth group will respond to the quadruple impulse Morse signalsrepresentedaby-the letters V, X, Q, J,

l B, and H. It will be noted that there are four additional solenoids which are indicated. by the reference letters These additional solenoids may be used for special signals and one of them may be employed, if so desired, to

63d. In other words if the first impulse of a signal is a dot, the relay 63a will not'be energized and its armature 66a will remain in the right hand position as shown in the diagram. If, however, the impulse is of relatively long duration, representing a dash, the armature 660, will be drawn to the left.

Similarly the armatures 66?), 660, and 66d of the polarized relays 63b, 63c, and 6303, will remain in their normal righthand position unless they are drawn to the lefthand position by impulses of long duration in the second, third and fourth impulses respectively of the signal. The armature 66a normally engages a contact point on a conductor 67 whichis permanently connected to a contact member 68 carried by the armature 666. When the armature 66a is in the lefthand or dash position it engagesa contact point on a conductor 69 which is permanently connected to a contact member 70 on the armature 66b. The contact members 68 and 70 are insulated from each other and normally engage contacts on conductors 71 and 72 respectively which are permanently connected to contact'members 73 and 74 respectively, carried by the armature 660. When the armature 66b is thrown to the left the members 68 and 7 O engage contacts carried by conductors 75 and 76 respectively and the latter are permanently connected to contact members 77 and 78 respectively carried by the armature 660. contact members carried by the armature 660 are insulated one from another. .Normally the contact members carried by the armature 66c engage contacts carried by conductors 7 9, 80, 81, and 82 respectively which are permanently connected to contact members. 83, 84;, 85cand 86 respectively carried by the armature 6612. When the armature 660 is moved to the left the members 73, 7 4, 77 and 78 engage contact points carried by conductors 87, 88, 89 and 90 respectively, and the latter are permanently connected to contact members 91,92, 93, and 94 respectively car ried by the armature 66th all of the contact members carriedby the armature 66d are insulated from one another. Normally the contact members carried by the armature 66d engage contact points carried by conductors 95-, 96,97, 98, 99, 100, 101, and 102 respectively. But when the armature 66d is'moved to the left the contact members borne by the armature 66d engage contact points carried It will be understood that all the .noid T has one terminal thereof connected to the conductor 69 while the other terminal is extended in position to be engaged by the armature 111a when the latter is attracted by the relay 60a. The armature 111a is connected to the ground wire 61. The solenoids A, M, N, and I, are connected at one end to conductors 75, 76, 72 and 71 respectively while at the other end they are connected to contact points which lie in the path of the armature 111b of relay 60b. Armature 111?) is connected to the ground wire 61 and hence when the armature 60b is energized the solenoids in the second group will all be connected to ground. Similarly the solenoids in the third group are connected at one end to conductors 79, 80, 81, 82, 87, 88, 89, and 90 respectively, while at the opposite end they are respectively provided with contact points which lie in the path of a grounded armature 1110 of the relay 60c. Thus when the relay 600 is energized all the solenoids in the third group will be connected to ground. The solenoids in the fourth group are connected at one end to the conductors 95 to 110 inclusive respectively, and at the opposite end are provided with contact points adapted to be engaged by a grounded armature 111d of relay 60d. Thus when the relay 60d is energized all of the solenoids in the fourth group will be connected to ground.

Before proceeding to a description of the operation of my apparatus attention must be called to a resetting relay 112, one terminal of which is connected by a line 113 to the battery line 15 while the other terminal is connected to the armature 66a. The resetting relay being in the primary circuit is operated whenever a letter is printed. When the resetting relay 112 is energized its armature 114 is attracted, closing a circuit at the contact point 115. This circuit includes the negative or resetting windings of all the polarized relays in the system. The circuit [may be traced from the battery line 15 through a line 116 and the negative wind- .ings of the relays 31a, 316, 310, and 31d which are connected in series, while from it the polarized relays will be actuated to reset their respective armatures to the normal position shown in the diagram.

We may now proceed to an explanation of the operation of the apparatus. If a single impulse signal comes over the line the relay 11 will be energized, attracting the armature 12 and closing the circuit of the dash relay 19. At the sameinstant the polarized rela 31a will draw its armature 38a to the le t and the relay 32a will attract its armature 39a. As soon as relay 38a makes contact with the contact point 40a the relay 30a, will be energized attracting armature 34a and connecting the space relay 17 to ground. However, the circuit of space relay 17 will re-' main interrupted as long as the line impulse continues to energize the relay 11. If the impulse is of suflicient duration to permitthe slow acting dash relay 19 to draw its armature 20 into contact with the contact point 21, a circuit-will be established from the battery line 15 though the armature 20 and line 23 to the contact member b, whence current .will flow by way of line 62a, through the positive winding of the polarized relay 63a. This will serve to swing the armature 66a tothe left whereby it will engage the conductor 69. If on the other hand the impulse is of short duration the dash relay 19 will not have time to close the circuit of the positive winding of therelay 63a, and the armature 66a will remain in normal position. Immediately after the impulse has ceased to energize the relay 11, the armature 12 will be withdrawn by the spring 12 closing the circuit through the spacerelay 17. The space or time interval between signals should be sufficient to permit the armature 24 of the space relay to be drawn into engagement with the contact point 25. As soon as such contact is effected current flows from the battery 16, through the battery line 15, armature 24, line 27, contact member 54b, line 59a, and thence through relay 60a to ground. This serves to attract? the armature 111a which connects the solenoids T and E to ground. Current then flows from the battery line 15 through line 113, and resetting relay 112, to armature 66a, and thence, if the armature is in normal or dot'position, the current continues through conductor 67, and solenoid E to ground by way of the armature 111a. If on the other hand the impulse had been of sufficient duration to swing the relay 66a to the left, the current from the armature 66a would ass through the conductor 69 and thence y way of solenoid T and armature 111a to ground. Thus eitherthe solenoid E vor the solenoid T would be energized depending upon whether the si al was a single dot or a single dash. This through the relay 112 would close armature- 114 upon contact point 115 thereby sending an impulse through all the negative windings of the polarized relays and resetting the arcurrent in passing recalled matures 66a and 38a to the normal or righthand position, thus deenergizing relay 30a and permitting armature 3 10, to return to normal position under tension of spring 56a.

- Movement of armature 34a would break the I circuit-through relay 17 and its armature would break the current through relay a permitting armature 111a to return to normal open position under suitable spring tension, and similarly relay 112 would be deenergized through the break in 1ts circult at armature 111a, permitting armature 114 to g'eturn to normal open position.

If a double impulse signal were received over the line the first impulse would operate the relays 32a and 31a and the latter in turn would operate the relay 30a as explained above, and also, as explained above, a long impulse or dash would move the armature 66a to the left, while a short impulse or dot would not disturb said armature out of normal position. As t e interval between impulses within a signal is not long enough to cause the space relay 17 toactuate its armature 2 1, the relay 60a would not be actuated during the interval between the first and second impulses. The second impulse would then pass from the relay 11, through line 33a, armature 34a, contact point 50a, line 51a, armature 39a, contact point 52a, and line 33b to armature 311; thence'the impulse would pass through the positive winding of the relay 31b and through the relay 32b. The armature 381) would then be attracted to the left, closing a circuit through the relay 301), which would attract armature 34b to the left. This would introduce another break in the circuit through the relay 60a, and another break in the circuit through the positive winding of relay 63a. However, because the relay 63a'is polarized, its armature 66a would remain in the position controlled by the first impulse. If the second impulse were of suflicient dura-' tion to close the armature 20 upon the contact point 21, current would now flow from the battery line 15 through the armature 20 and line 23 to the contact member 55?), and thence by way of contact member (for it will be that the armature 34:?) has now assumed its lefthand position) to the contact member 550 and by way of line 62b to the positive winding of the polarized relay 63b.

carried thereby would make contact with conductors and 76, respectively. As'soon 'as the second impulse ceased, the spaced interval between this impulse and the first impulse of the next signal would be sufficient.

toactuate the relay 17 and current would now flow from the battery line 15 by way of armature 24 and line 27 to contact member 54?),

' thence by way of contact point 64?) to contact member 5 10', and from the latter by way of line 596 through the relay 60?). As soon as the relay 60b is energized, solenoids A, M,N, and I will be connected to ground through arm ature 111?) and currentwill flow as before from the armature 66a, either through conductor 67 or 69 depending upon whether the first impulse was a dot or a dash and thence either through the contact member 68 and conductor 71 or 75, depending upon whether the second impulse was a dot or a dash, or through the contact member 70 and either the conductor 72 or 76, depending upon the position of the armature 66?), through one of the solenoids of the second group to ground. 7 Thus by combining the positions of the armatures 66a and 666 any one of four possible paths are provided for the flow of current from the armature66a to ground, and as each path in cludes a solenoid, I thus provide a means oi selecting the particular solenoid desired in accordance with the particular combination of dots and dashes in the signal.

If a triple impulse signal is sent over the line the first impulse will control the position of armature 66a, the second impulse will control the position of armature 66?), while the third impulse will control the position of the armature 66a. The control of armatures 66a and 66?) has already been described. The control of armature 660 is as follows: If the third impulse is of long duration the circuit closed by the armature 20 may be traced through the line 23 to contact member 556, thence through contact point 65?), to contact member 550, and in view of the fact that the third impulse has swung the armature 340' to the left the current will now flow by way of contact point 650 to contact member 55d and thence through contact point 58d and line 620 through the positive winding of the polarized relay 630 to ground. This will throw the armature 660 to the left. If on the other hand, the duration of the third impulse. is not sufiicient to close the armature 20 upon the contact point 21 before the circuit of the space relay 19 is interrupted by release of the-armature 12, the armature 660 will remain in the normal position illustrated. At the end of the signal, the space relay 17 which has not had time between previous impulses in the signal to; draw its armature 24: into. contact with the contact point 25,. will now have time to efiect such contact and establish a circuit which may be traced from battery line 15 through armature 24, line 27, contact member 54b, contact point 64?), contact member 540, contact point 640,

to contact member 54d. Thence the circuit will be completed through contact point 576, 7

line 590, and relay 600to ground. The armature 1110 will then be actuated to connect all the solenoids in the third group to ground, but current can pass through only one of the solenoids, depending upon the respective positions of the' armatures 66a, 66b, and 660. For example let us suppose that the signal consisted of a dot and two'dashes representfirst impulse, being of short duration, Would not have caused the armature 66a to move out of normal position but the other two impulses would have moved the armatures 66b and 660 respectively to the left. With said armatures in that position there would be only one path for current to flow through from the armature 66a to 'ground. This path would be as follows: From the armature 66a, through the conductor 67, contact member 68, conductor 7 5, contact member 78, conductor 87, solenoid W, armature 1110, to ground.

In case the signal consisted of four 1mpulsesthe first three impulses would pursue the paths described above but the fourth 1mpulse would follow a different course. The fourth bank, it will be recalled, contains only one relay because it is not necessary to provide for switching from this relay to another if the system is to be used for a maximum of four impulses to a signal. Obviously if five, six or more impulses were to be used in a signal there would have to be a bank of relays for each impulse of the signal, but the last bank in every case would consist of a single polarized relay. In considering the action of a four impulse signal we need not trace the course of the first three impulses, as that has already been described. The fourth impulse passing through the relay 11 would by-pass the relays 31 and 32 in each bank and in bank a would pass from the armature 340 through contact point 500, line 510, armature 39c, contact point 520, line 33d, through the positive winding of relay 31d, to ground. Th s would cause the armature 38d to swing to the left breaking engagement between contact members 5403 and 57d and between contact members d and 58d," and make contact between member 54d and contact point 64d and between member 55d and contact point 65d, thereby establishing connection with-relays 60d and 63d respectively. If the fourth impulse is a dash, a circuit will be established from the battery line 15 through armature 20, line 23, contact member 5511, contact point 6511, contact member 55c, contact point 650, contact member 55d,

contact point 65d to the positive winding of the polarized 'relay 63d. Similarly at the end of the fourth impulse the'space relay 17 will establish a circuit througharmature 24,

' line 27, contact member 546, contact point 646, contact member 540, contact point 640, oontactrmember' 5412, contact point 640?, line 59d through rela 60d to ground. This would connect with gadund all of the solenoids of the fourth group through the armature 111d. But only one of the solenoids would be energized depending upon the relative positions of the armatures 66a, 66b, 66c, and 6603. If for instance, the signal dashdot-dashdot, were to come in over the line 10 the solenoid C would be the only one that would respond to the signal. The first impulse would throw the armature 66a to the left, the second armature 66?) would remain stationary, the

third armature 660 would be thrown to the left and the fourth armature 6641 would remain stationary. The course of the current flowing from armature 66a would be as follows: From conductor 69, through member 70, conductor 72, contact member 74, conductor 89, contact member 93, conductor 101, solenoid C and armature 111d to ground. Similarly the course of the current for any other combinations of dots and dashes in four impulses will be found to pass through one and one only of the solenoids in the fourth oup.

It will be obvious that many changes could be made in the construction, form and arrangernent of the apparatus, and hence the particular embodiment of my invention shown in the drawings and described above shouldbe considered as illustrative and not restrictive, while the principles and scope of my invention are defined in the following claims.

I claim:

1. In an electric receiving apparatus adapted to receive intermittent electric impulses of two kinds, a pair of electromagnets, a normally open electric circuit, a switch normally connecting one of said magnets into the circuit, means controlled by one of said kinds ofimpulses for throwing the switch to connect the other of said magnets into the circuit, and means automatically operable during intervals between said impulses for closing said circuit to energize the magnet connected therein.

2. In a printing telegraph receiver adapted to receive intermittent electric impulsesof two kinds, a pair of printing-controlling electromagnets, a normally open electric circuit, a switch normally connecting one of said magnets into the circuit, means controlled by one of said kinds of impulses for,throwing the switch to connect the other of said magnets into the circuit, and means automatically operableHuring intervals between said impulses for closing said circuitto energize the magnet connected therein.v

3. In a printing telegraph receiver adapted to receive intermittent electric impulses of two kinds, 2:. pair of printing-controlling electromagnets, a normally open electric circuit, a switch normally connecting one of said magnets into the circuit, means controlledby one of said kinds of impulses for throwing the switch to connect the other of said magnets into the circuit, means automatically operable during intervals between said impulses for closing said circuit to'energize the magnet connected therein, and means for restoring the switch to normal position and opening said circuit when either of said magnets has been energized.

4. In a printing telegraph receiver adapted to receive intermittent electric impulses of'variously long and short duration, a pair of printing-controlling electromagnets, a normally open electric circuit, a switch for alternately connecting one or the other of said magnets into the circuit, a slow acting relay for controlling said switch, said relay including means for retarding the growth of the magnetizing current thereof whereby the relay w'ill respond to said long impulses but not to said short impulses, and means actuated during intervals between said impulses for closing-such circuit.

5. In a printing telegraph receiver adapted to receive intermittent impulses of variously long and short duration, a pair of printing-controlling electromagnets, a normally open electric circuit, a switch for alternately connecting one or the other of said magnets into the circuit, a slow acting relay for controlling said switch, said relay including means for retarding the growth of the magnetizing current thereof whereby the relay will respond to said long impulses only, means actuated during intervals between said impulses for closing said circuit to energize the magnet therein and means operating to restore the switch to 'normal position and open said electric circuit when either of said magnets has been energized.

6. In an electric receiving apparatus, the combination of a slow-acting relay responsive only to electric impulses exceeding a predetermined duration, a slow-acting relay responsive only to inter-impulse intervals exceeding a pre-determined duration,"each of said slow acting relays including means for retarding growth of the magnetizing current thereof, a local circuit including a plurality of branch circuits, and switch mechanism for selectively controlling said branch circuits,said switch mechanism being connected with both of said relays and controllable conjointly thereby.

7. In an electric receiving apparatus, the combination of a relay responsive to electric impulses exceeding a pre-determined duration, a relay responsive to inter-impulse intervals exceeding a pre-determined duration, each of said relays including means for retarding growth of the magnetizing current thereof, a selective relay operated by electric impulses and controlling the two relays first named, a local circuit including a plurality of branch circuits, and switch mechanism connected with said local circuit for selectively controlling the branch circuits, said switch mechanism being connected with both of said first named relays and controllable conjointly thereby.

8. In a printing telegraph receiver adapted to be operated by electric impulses, a main relay controlled by the signal impulses, two slow acting relays adapted to be selectively controlled by the main relay, each of said relays including means for retarding growth of the magnetizing current thereof, one of the slow acting relays responding only to imbranches to select one of said magnets, and

means controlled by the other slow acting relay for completing the local circuit through the magnet thus selected.

9. In a printing telegraph receiver adapted to be operated by electric impulses, a main relay controlled by the signal impulses, two slow acting relays selectively controlled by the main relay, each of said relays including means for retarding growth of the magnetizing current thereof the first of said slow act ing relays responding only to impulses exceeding a pre-determined duration and the second of said slow acting relays responding only to inter-impulse intervals exceeding a pre-determined duration, a local circuit including a plurality of branches, an electromagnet connected with each branch, means controlled by thefirst of said slow acting relays for selectively inter-connecting said branches to select one of said magnets, and means controlled by the other slow acting relay for completing the local circuit through the magnet selected.

' 10. In a printing telegraph apparatus adapted to receive electric impulse signals, said signals being differentiated by number and duration of impulses with "intervals between signals of greater. duration than interimpulse intervals within signals, a series of working circuits, self locking inter-connect ing switches, for selectively inter-connecting the working circuits, actuating switches for completing a circuit through the particular working circuit selected by the inter-connect-r ing switches, a primary slow acting relay responsive only to impulses exceeding a pre-determined minimum duration, a secondary slow acting relay responsive only to inter-signal intervals, each of said slow acting relays including means for retarding growth of the the primary relay, locking mechanism for holding the shunt line in connection with the 1 main line, the shunt line. being formed with a gap adapted to be opened by actuation of the secondary relay and closed when the latter relay is deenergized, whereby a path will be provided for the next succeeding impulse of the signal through the shunt line.

12. In a printing telegraph receiver adapt- .ed to receive electric impulse signals from a main line, a primary relay, a'secondary relay, said relays being adapted to be actuated by a line impulse, a shunt line adapted to be connected to themain line by actuation of the primary relay, locking mechanism for holding the shunt line in connection with the main line, the shunt line being formed with a gap adapted to be opened by actuation of the secondary relay and closed when the latter relay is de-energize'd whereby the next succeeding impulse of the signal will pass through the shunt line, and -means for restorin said relays to normal position.

13. n a printing telegraph receiver adapted to receive electric impulse signals over a main line, a primary relay, a self-locking relay, a secondary relay, the last two relays being normally connected to the main line under control of the primary relay, means'operated by actuation ofthe secondary relay for establishing an independent connection from the mainline therethrough, the self-locking relay operating to efiect-actuation of the prinaryrelay, whereby normal connection be. tween the main line and the self-locking relay will be broken, and a shunt line adapted to be connected to the main line by actuation of the primary relay, said shunt line having a normally closed gap adapted to be bpened by actuation of the secondary relay and closed when said secondary relay is de-energized, whereby the first impulse of a signal will operate to connect the shunt line with the main line and open the gap until the impulse ceases, whereupon the gap will close to provide a path for the next succeeding impulse of the signal through the shunt line.

14. In a printing telegraph receiver adapted to receive electric impulse signals over a main line, with intervals of predetermined minimum duration between signals, a rimary relay, a sel f-lockin relay, a secon ary relay, the last two relays eing normally connoted to the main line under control of the primary relay, means operated by actuation of the secondary relay for establishing an independent connection from the main line therethrough,'the self-locking relay operating to effect actuation of the primary relay, whereby normal connection between the main line and the self-locking relay will be broken, and a shunt line adapted to be connected to the main line by actuation of the primary relay, said shunt line having a normally closed gap adapted to be opened by actuation of the secondary relay and closed when said secondary relay is de-energized, whereby the first impulse of a signal will operate to connect the shunt line with the main line and open the gap until the. impulse ceases, whereupon the gap will close to provide a path for the next succeeding impulse of the signal through the shunt line, and means controlled by inter-signal intervals for restoring said relays to normal position.

Signed at New York in the county of New York and State of New York this thirteenth day of April A. D. 1927.

ROBERT TEVIS. 

